Method for operating a gas concentration monitoring system, gas-measuring device, central unit, gas concentration monitoring system as well as computer program product

ABSTRACT

A method is provided for operating a gas concentration monitoring system as well as a gas-measuring device, a central unit, a gas concentration monitoring system as well as computer program product. The safety of persons or the safety of a situation is determined with respect to at least one hazardous gas. The concentration of the gas is provided to a memory and analysis device. A measured value rating number is determined for a preset period of use. A number of instances, of the measured concentration values exceeding of a preset gas concentration limit value is input. A safety code is determined from at least one of: the measured concentration values, the measured value rating numbers and from the a total number of instances in which a gas concentration limit value was exceeded.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a U.S. National Phase Application of InternationalApplication PCT/EP2012/073844 filed Nov. 28, 2012 and claims the benefitof priority under 35 U.S.C. § 119 of German Patent Application DE 102011 119 570.3 filed Nov. 28, 2011, the entire contents of which areincorporated herein by reference.

FIELD OF THE INVENTION

The present invention pertains to a method for operating a gasconcentration monitoring system for detecting the gas concentration ofat least one gaseous substance, in which a safety code for assessing thesafety situation in a predetermined operating area is determined. Thepresent invention pertains, furthermore, to a gas-measuring device aswell as to a computer program product for carrying out the methodaccording to the present invention.

BACKGROUND OF THE INVENTION

Gas-measuring devices, especially portable gas-measuring devices, areused to monitor the gas concentration of at least one gaseous substancein a predetermined operating area, e.g., an industrial plant, such as arefinery. The gaseous substances may be, e.g., carbon monoxide, hydrogensulfide, oxygen or other toxic gaseous substances. These gas-measuringdevices have for this one or more sensors in order to measure the gasconcentration of the gaseous substance in question in the ppm range.Such gas-measuring devices usually have two limit values, which triggeran alarm. These are a low limit value, where a pre-alarm (also calledA1) is triggered when this is exceeded, and a high limit value, where amaster alarm (also called A2) is triggered when this is exceeded. Thegas-measuring device generates an acoustic and/or optical alarm in orderto warn the user of the gas-measuring devices in response to theexceeding of a limit value, for example, a workplace limit value (WLV)or a lower explosion limit (LEL), which sets the maximum allowableconcentration of a gaseous substance. To guarantee reliable operation ofthe gas-measuring devices, it is necessary for the gas-measuring devicesto be checked regularly. For example, so-called bump tests are carriedout for this at relatively short intervals and calibrations atrelatively long intervals compared to the former. These bump tests andcalibrations are carried out with so-called docking stations, whichadmit for this an inert gas, e.g., nitrogen, or fresh air, and a testgas containing the gaseous substance to be detected to the sensor of agas-measuring device. However, it is desirable to obtain moreinformation on the safety situation in a predetermined operating area.

SUMMARY OF THE INVENTION

An object of the present invention is therefore to provide a method forobtaining more safety-relevant information for assessing the safety ofpersons.

The object of the present invention is accomplished by a method fordetermining the safety of the person from at least one gas threateningthe person and especially at least one toxic gas and/or at least onecombustible gas and/or oxygen deficiency and/or oxygen excess, saidmethod having the steps of:

-   -   inputting the concentration of each of the at least one gas        determined by the plurality of gas-measuring devices into a        memory and analysis means;    -   determination of a measured value rating number for a preset        period of use of the gas-measuring device in question in the        memory and analysis means from the measured values for the        concentration of each of the at least one gas;    -   inputting a number of instances in which a preset gas        concentration limit value is exceeded by the measured value for        each of the gas-measuring devices into a data; and    -   determination of a safety code for rating the safety        situation/safety of persons for a plurality of measurement sites        as a whole, at which the measurements were performed by the        gas-measuring device, from the measured values of the plurality        of gas-measuring devices and/or from the measured value rating        numbers determined from the measured values of the plurality of        gas-measuring devices and from the total number of instances in        which a gas concentration limit value is exceeded, which is        determined from the measured value of the plurality of        gas-measuring devices.

Further, the object of the present invention is accomplished by a methodwith the steps of:

-   -   inputting measured values for the concentration of each of the        at least one gas into a memory and analysis means,    -   determination of a measured value rating number derived for a        preset period of use of the respective gas-measuring device from        the measured values for the concentration of each of the at        least one gas in the memory and analysis means, inputting a        number of instances in which a preset gas concentration limit        value was exceeded by the measured values for each of the        gas-measuring device into a memory, and    -   determination of a safety code for rating the safety        situation/safety of persons for a plurality of measurement sites        as whole, at which the measurements performed by the        gas-measuring device were carried out, from the measured values        of the plurality of gas-measuring devices and/or from the        measured value rating numbers determined from the measured        values of the plurality of gas-measuring devices and from the        total number of instances in which a gas concentration limit        value was exceeded, which was determined from the measured        values of the plurality of gas-measuring devices.

The methods consequently use data, e.g., in the form of one or more datasets, which were obtained when gas concentration measurements werecarried out with a plurality of gas-measuring devices, e.g., during thetime during which the one user or the users carried with him/them, e.g.,a portable gas-measuring device each in an operating area in order to bewarned, if necessary, of excessively high concentrations of a toxicgaseous substance. Data are detected and recorded continuously in theprocess. As an alternative, a data set can then be generated, e.g., by agas-measuring device when the gas-measuring device has detected a gasconcentration that is above a permissible limit value, e.g., theworkplace limit value (WLV) or a lower explosion limit (LEL). Besidesthe exceeding of the limit value, the data set may contain moreinformation, e.g., the type of the gaseous substance, if, e.g., aplurality of different gaseous substances can be detected with thegas-measuring device, the extent to which the limit value is exceeded,the duration for which the limit value is exceeded, as well as a dose,which is determined from the extent and the duration to which and forwhich the limit value was exceeded.

The data are then transmitted from each gas-measuring device to thememory and analysis means. The transmission of the data may take place,e.g., by a data storage medium, e.g., a USB stick, on which the data arefirst transmitted from the gas-measuring device, and they are thentransmitted from the USB stick into the memory and analysis means. As analternative, transmission of the data may take place via electriccontacts of the gas-measuring device, in which case, e.g., a dockingstation for performing bump tests or calibrations have correspondingmating contacts in order to form an electrically conductive connectionfor transmitting the data. The docking station itself may, in this case,have a data bank, or the docking station is connected with the databank, e.g., via a computer network. Finally, the transmission of thedata set may also take place in a wireless manner, so that it is notnecessary to establish an electric contact.

A safety code, which contains information on how often a limit value wasexceeded and/or how conscientiously (frequently) the gas-measuringdevices were checked, so that their reliable operability is guaranteed,on the basis of the information contained in the data on exceeding ofthe limit value and/or on checks of the gas-measuring devices that werenot performed, is then determined from the data. The safety code thusmakes it possible to assess the safety situation in an operating area,e.g., an industrial plant, such as a refinery, because leakage of gasfrom the industrial plant is also detected by detecting instances inwhich a limit value was exceeded.

The safety code may, furthermore, be observed over a rather long periodof time in order to recognize changes in the safety situation. Inaddition, the safety code can be compared with safety codes of otherareas of a plant or also of plants among each other in order to thusobtain additional information.

The safety code is a single number that expresses the safety situationas a summary of a plurality of factors in the form of a sum parameter.Different colors may also be assigned to different value ranges of thesafety code, e.g., green to a quite safe safety situation, yellow to aprecarious safety situation, which requires increased attention, and redto a safety situation that requires immediate action.

Provisions are preferably made for the measured value rating numberderived for a preset period of use of the respective gas-measuringdevice to be an average determined for the preset period of use. Thedefinition of the period of use also covers the interval between uses ofa gas-measuring device. A use interval is the period from the time thegas-measuring device is put into operation by a user, e.g., at thebeginning of a shift, until the end of use by the user, e.g., at the endof the shift. Other variables may also be used as the basis for themeasured value rating number instead of the average.

Provisions are preferably made for always determining the safety code byweighted addition of the measured values and/or the measured valuerating number for the preset period of use of the respectivegas-measuring device, with a derived measured value rating number and ameasured value rating number determined from a number of instances inwhich a gas concentration limit value was exceeded by the measuredvalues together with an identification code of the respectivegas-measuring device.

Weighting of the events can be performed by a weighted addition, sothat, e.g., the events exceeding the limit value are taken into accountwith a greater weight than is the measured value rating number.

Weighted addition leads to an intuitively easy-to-understand safetycode, in which the number zero is a very good value and the scale of thesafety code is upwardly open, i.e., it may assume high numbers asdesired. Thus, it is not suggested that there is a 100% risk, unlike inthe case of data expressed in percentage, which can assume a value fromzero to 100%.

Further, provisions are preferably made for the method to additionallyhave the following step: Inputting of the duration of the detectedexceeding of the gas concentration limit value preset period of use ofthe respective gas-measuring device. This is input into a memory andanalysis means from each of the gas-measuring devices, and provisionsare preferably made for the determination of the safety code to beperformed such that the duration of the detected exceeding of the gasconcentration limit value is taken functionally into account andespecially by weighted addition of the duration.

The duration of the detected exceeding of the gas concentration limitvalue within the use interval of the gas-measuring device is defined asthe average duration of the alarm, e.g., the duration of a pre-alarm(A1) or of a master alarm (A2) of the gas-measuring device or pergas-measuring device in case of a plurality of gas-measuring devices inminutes, i.e., the total alarm duration of all gas-measuring devices ofa fleet (group) of gas-measuring devices, divided by the number ofgas-measuring devices and standardized for the number of minutes ofalarm per use interval, e.g., one day. The duration of one or moreexceeding of the limit value event is determined, doing so relative to ause interval of the gas-measuring device.

Further, provisions are preferably made for the step of determining thesafety code to comprise:

-   -   determination of the number of checks performed on each        gas-measuring device in a checking interval, especially of the        calibrations and/or bump tests;    -   comparison of the number with the checks determined in a        checking interval, especially of the calibrations and/or bump        tests, with a desired value of the number of checks in a use        interval, and    -   taking the difference between the number of checks determined        and the desired value into account in the determination of the        safety code.

The checks not performed are determined by comparing the number ofchecks performed with the desired value. Skipped checks are detected,and they are detected relative to a use interval of the gas-measuringdevice. Calibrations are identified here as complete checks includingthe determination of all calibration parameters, while a bump test isdefined as a kind of rapid test, in which a function test is performedby exposing the sensor to a test gas without determination ofcalibration parameters.

Provisions are preferably made for the step of taking into account thedifference to include the differently weighted addition of the number ofskipped calibrations and bump tests. This can be performed by usingweighting factors, a first weighting factor to the skipped calibrationsand a second weighting factor to the bump tests. For example, the secondweighting factor may be greater than the first weighting factor. Thesecond weighting factor may thus be 1.5 to 3 times greater than thefirst weighting factor. For example, the second weighting factor may betwice the first weighting factor in order to have skipped bump tests bereflected especially strongly in the safety code. Further, provisionsare preferably made for the step of determining the safety code toinclude the differently weighted addition of the number of skippedcalibrations and bump tests. This can be performed by using weightingfactors, wherein a first weighting factor is assigned to the skippedcalibrations and a second weighting factor is assigned to the bumptests. For example, the second weighting factor may be greater than thefirst weighting factor. Thus, the second weighting factor may be 1.5 to3 times greater than the first weighting factor. For example, the secondweighting factor may be twice the first weighting factor in order tohave skipped bump tests be reflected especially strongly in the safetycode.

To achieve a further refinement of the validity of the safety code,provisions are preferably made for the step of determining the safetycode to include the weighting of the number of skipped calibrations witha first weighting factor, the weighting of the number of skipped bumptests with a second weighting factor, and the weighting of the durationof the detected exceeding of the gas concentration limit value with athird weighting factor. The third weighting factor may be 2 to 5 timesgreater than the first weighting factor. For example, the thirdweighting factor may be 3 times the first weighting factor and 1.5 timesgreater than the second weighting factor, so that especially criticallimit value exceedings affect the safety code especially strongly.Further, informative information can be obtained if filtering of thedata with respect to the model of the gas-measuring device and/or thefield of use of the gas-measuring device and/or the users of thegas-measuring device and/or the user groups of the gas-measuring deviceand/or the period of use of the gas-measuring device is performed fordetermining the safety code. It is thus possible to determine safetycodes that are related to a certain model of gas-measuring device of afleet with different device models and thus make it possible to comparedifferent device models. Further, safety codes can be determined thatare related to the field of use of the gas-measuring device, i.e., e.g.,to a certain area of industrial premises, so that special safetysituations can be assigned to certain geographic areas. In addition,user-related or user group-related safety codes can be determined, sothat it can be determined whether the safety situation of certain usersor user groups differs significantly from that of other users or usergroups.

To obtain data unambiguously assigned to a use interval, provisions arepreferably made for a reset signal to be generated, upon the receipt ofwhich the gas-measuring device generates new data after transmission ofthe exiting data. The reset signal is generated for this when, e.g., auser puts down the gas-measuring device. The memory of the gas-measuringdevice is then deleted and new data can be generated when thegas-measuring device is put into operation again.

Further, provisions are preferably made for the data to contain atleast:

-   -   a gas-measuring device identification number of the        gas-measuring device and/or    -   a gas-measuring device model number of the gas-measuring device        and/or    -   gas-measuring device measured data detected with the gas sensor        within a use interval of the gas-measuring device and/or    -   an operating time, especially duration of a use interval, of the        gas-measuring device, and/or    -   acceleration values detected with an acceleration sensor within        a use interval of the gas-measuring device and/or    -   a user identification number for identifying a user of the        gas-measuring device.

The respective data can be assigned to the respective gas-measuringdevices with a gas-measuring device identification number of thegas-measuring device. By logging which user is taking whichgas-measuring device of a fleet of gas-measuring devices with him, thismakes it possible to perform an especially simple user- or usergroup-related analysis of the safety codes.

Simple assignment of data to devices of the same model of a fleet ofdevices and thus a device-specific analysis of safety codes is possiblewith a gas-measuring device model number.

The gas concentration measured data detected with the gas sensor withina use interval of the gas-measuring device make it possible to assesswhether, e.g., an exceeding of the limit value occurred abruptly orwhether it developed only gradually, which can give indications as tothe cause of the exceeding of the limit value.

The operating time of the use of the gas-measuring device can be takeninto account in the assessment of the safety code by the operating time,especially the use interval duration. Thus, the probability ofmalfunctions of the gas-measuring device increases with increasingoperating time, e.g., in case of the depletion of batteries, which areused to supply the gas-measuring device with energy.

It can be assessed with the acceleration values whether thegas-measuring device was subject to acceleration values during a useinterval that could lead to mechanical damage to the gas-measuringdevice or components thereof.

Finally, a user identification numbers simplifies the identification ofa user of the gas-measuring device and optionally the assignment of auser to a user group and thus makes possible a person-specificassessment of the safety situation, which can possibly be improved byspecific training.

Further, a gas-measuring device as part of a gas concentrationmonitoring system belongs to the object of the present invention. Thegas-measuring device has a gas sensor for measuring the gasconcentration of at least one gaseous substance.

In addition, the gas-measuring device has a comparison means. Thecomparison means is designed to compare a measured value detected withthe gas sensor in the form of gas concentration measured data with a gasconcentration limit value, e.g., a workplace limit value (WLV) or alower explosion limit (LEL).

The gas-measuring device has, furthermore, a monitoring means. It isdetected with the monitoring means whether a prescribed checking of theoperability, especially of the calibrations and/or bump test of thegas-measuring device, was performed within a checking interval.

A data set generation module of the gas-measuring device is connectedwith the comparison means and the monitoring means. The data setgeneration module generates data when the measured value determined inthe form of gas concentration measured data exceeds the gasconcentration limit value, and/or when a prescribed checking of theoperability, such as calibration and/or a bump test were not performedwithin a checking interval.

Finally, the gas-measuring device has a gas-measuring device interfacefor transmitting the data, which is preferably connected for this withthe data generation module. As an alternative or in addition, provisionsare preferably made for the gas-measuring device to have a memory andanalysis unit for analyzing the data, in order to determine a safetycode for rating the safety situation in a predetermined operating areaby analyzing the data. The memory and analysis unit has a designanalogous to that of the analysis module explained below, but the memoryand analysis unit is assigned to the gas-measuring device rather than tothe memory and analysis means. However, the same advantages and designpossibilities are analogously obtained as in the analysis module.

Provisions are preferably made for the memory and analysis unit to bedesigned to determine the number of checks performed on thegas-measuring device during a checking interval, especially of thecalibrations and/or bump tests, for comparing the number of checksdetermined during a checking interval, especially of the calibrationsand/or bump tests, with a desired value for the number of checks duringa checking interval, and/or for taking into account the differencebetween the number of checks determined and the desired value in thedetermination of the safety code.

Provisions are preferably made for the memory and analysis unit to bedesigned to take into account the difference of the skipped calibrationsand bump tests.

The gas-measuring device preferably has an acceleration sensor fordetecting accelerations acting on the gas-measuring device. It can thusbe detected whether the gas-measuring device was subjected toaccelerations, due to improper use, which could lead to damage to thegas-measuring device or components thereof.

The gas-measuring device is preferably designed to generate new dataupon receiving a reset signal. The memory of the gas-measuring device isdeleted upon receipt of the reset signal and new data can be generatedwhen the gas-measuring device is put into operation again.

In addition, the data set generation module of the gas-measuring deviceis preferably designed to degenerate data, which contain at least:

-   -   a gas-measuring device identification number of the        gas-measuring device and/or    -   a gas-measuring device model number of the gas-measuring device        and/or    -   gas concentration measured values detected with the gas sensor        within a use interval of the gas-measuring device and/or    -   an operating time, especially use interval duration, of the        gas-measuring device and/or    -   acceleration values detected with an acceleration sensor within        a use interval of the gas-measuring device and/or    -   a user identification number for identifying a user of the        gas-measuring device.

This facilitates the analysis of the safety codes, as this was alreadyexplained above with reference to the method according to the presentinvention.

In addition, a memory and analysis means or central unit as part of agas concentration monitoring system belongs to the object of the presentinvention.

The memory and analysis means has an input interface. Data that aretransmitted from a gas-measuring device to a data bank of the centralunit can be input with the input interface. The data themselves wereobtained by means of a gas-measuring device, as this was alreadyexplained in the description of the method according to the presentinvention.

The memory and analysis means has a data bank module, which is designedto store and read out data.

In addition, the memory and analysis means has an analysis module, whichhas access to the data stored by the data bank module. The analysismodule is designed to analyze the stored data in order to determine thesafety code for rating the safety situation in a predetermined operatingarea.

Provisions are preferably made for the analysis module to be designed toform the safety code by a weighted addition of at least:

-   -   the number of skipped checks of the operability, especially of        the calibrations and/or bump tests, of the gas-measuring device,        and    -   the duration of the detected exceeding of the gas concentration        limit value within the use interval of the gas-measuring device.

As is explained in reference to the method according to the presentinvention, the duration of the detected exceeding of the gasconcentration limit value within the use interval of the gas-measuringdevice is defined as the average alarm duration, e.g., the duration of apre-alarm (A1) or of a master alarm (D2) of the gas-measuring device pergas-measuring device in case of a plurality of gas-measuring devices inminutes, i.e., the total alarm duration of all gas-measuring devices ofa fleet (group) of gas-measuring devices, divided by the number ofgas-measuring devices and standardized for the number of minutes ofalarm per day. For example, limit value exceedings can thus be takeninto account with a heavier weight than skipped checks. As was alsoexplained already in reference to the method according to the presentinvention, an intuitively easy-to-understand safety code is obtained bythe weighted addition.

Provisions are preferably also made for the analysis module to bedesigned to weight the number of skipped calibrations and bump testsdifferently.

As was explained in reference to the method according to the presentinvention, skipped bump tests can thus be reflected with an especiallyheavy weight in the safety code.

Further, provisions are preferably made for the analysis module to bedesigned to weight the number of skipped calibrations with a firstweighting factor, the skipped bump tests with a second weighting factor,and the duration of the detected exceeding of the gas concentrationlimit value with a third weighting factor.

As was explained with reference to the method according to the presentinvention, for example, especially critical limit value exceedings canaffect the safety code especially strongly.

Furthermore, provisions are preferably made for the analysis module tohave a filter function, with which the data can be filtered with respectto the model of the gas-measuring device and/or to the field of use ofthe gas-measuring device and/or to the users of the gas-measuring deviceand/or to the user groups of the gas-measuring device and/or to the usetime of use of the gas-measuring device for determining the safety code.

As was explained in reference to the method according to the presentinvention, it is thus possible, e.g., to determine safety codes that arerelated to a certain device model of a fleet of devices with differentdevice models and thus make it possible to compare different devicemodels. Further, safety codes can be determined that are related to thefield of use, i.e., a certain area of plant premises, of thegas-measuring device, so that special safety situations can be assignedto certain geographic areas. In addition, user-related or usergroup-related safety codes can be determined so that it is possible todetermine whether the safety situation for certain users or user groupsdiffers significantly from that for other users or user groups.

In addition, the memory and analysis means is preferably designed togenerate a reset signal, upon receipt of which a gas-measuring devicegenerates new data (a new data set).

As was explained in reference to the method according to the presentinvention, it is thus possible to obtain, e.g., data assigned to a useinterval.

As was also explained already in reference to the method according tothe present invention, data can be stored and read out with the databank module and analyzed with the analysis module, said data containingat least:

-   -   an identification number of the gas-measuring device and/or    -   a model number of the gas-measuring device and/or    -   gas concentration measured data detected with the gas sensor        within a use interval of the gas-measuring device and/or    -   an operating time, especially use interval duration, of the        gas-measuring device and/or    -   acceleration values detected with an acceleration sensor within        a use interval of the gas-measuring device and/or    -   a user identification number for identifying user of the        gas-measuring device, which facilitates the analysis of the        safety codes, as this was already explained above with reference        to the method according to the present invention.

The memory and analysis means may be designed solely to input data ofgas-measuring devices, to store them in a data bank and to analyze themin order to determine the safety code. As was described already, thetransmission of the data may take place by means of a data storagemedium, e.g., a USB stick, on which the data set is first transmittedfrom the gas-measuring device, and subsequently from the USB stick intothe data bank. As an alternative, the memory and analysis means, likethe gas-measuring devices, can be designed to transmit the data withwireless transmission, so that it is not necessary to establish anelectric contact. For example, the memory and analysis means, like thegas-measuring devices, may be designed such that when the distancebetween the memory and analysis means and one of the gas-measuringdevices drops below a minimum distance, both components establish awireless connection for data transmission and the data are subsequentlytransmitted from the gas-measuring device to the memory and analysismeans.

Provisions are preferably made for the memory and analysis means to havea device for checking the gas-measuring device for operability,especially for performing calibrations and/or bump tests. Such devicesfor checking the operability of the gas-measuring device are known andare also called docking stations.

The docking station has a plurality of mounting sites for agas-measuring device each. When inserted into a mounting site, a bumptest or a calibration can be performed with the docking station. Anelectric connection is formed between the docking station and thegas-measuring device in the mounting site via electric contacts of thedocking station. These electric contacts of the docking station and ofthe gas-measuring device form an interface connection for transmittingthe data that are archived in the memory of the gas-measuring device.

One or more of the docking stations are connected with the memory andanalysis means, e.g., a main central unit of the gas concentrationmonitoring system for exchanging data with one another, e.g., by acomputer network. A data bank with a computer, which has access to thedata bank and analyzes the data in order to determine the safety code,may be assigned to the main central unit.

As an alternative to this, one docking station or each of the dockingstations of the gas concentration monitoring system may be additionallyassigned to a data bank of its own with a computer, which has access tothe data bank of its own, but also to the other data banks, to determinethe safety code. Further, one docking station or each of the dockingstations may have an output means, e.g., in the form of a display, todisplay the safety codes determined besides displaying furtherinformation.

Finally, a gas concentration monitoring system with a memory andanalysis means, according to the present invention, and with a pluralityof gas-measuring devices according to the present invention as well as acomputer program product, which can be loaded into a computer of amemory, and an analysis means according to the present invention toexecute all steps of a method according to the present invention whenthe computer program product is executed in the computer, belongs to theaccomplishment of the object of the present invention.

Further advantageous embodiments of the present invention as well asexemplary embodiments herefor will be explained in more detail below inconnection with the drawing figures attached. Functionally similar partsor components are at times designated by the same reference numbers. Thevarious features of novelty which characterize the invention are pointedout with particularity in the claims annexed to and forming a part ofthis disclosure. For a better understanding of the invention, itsoperating advantages and specific objects attained by its uses,reference is made to the accompanying drawings and descriptive matter inwhich preferred embodiments of the invention are illustrated.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings:

FIG. 1 is a schematic view of the design of an exemplary embodiment of agas concentration monitoring system according to the present invention;

FIG. 2 is a schematic view of the design of an exemplary embodiment of adocking station according to the present invention; and

FIG. 3 is a schematic view of the design of an exemplary embodiment of agas-measuring device according to the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Reference is first made to FIG. 1.

The gas concentration monitoring system 2 has a fleet (group) ofgas-measuring devices with a plurality of gas-measuring devices 8 with agas sensor 10 each for detecting at least one gaseous substance, ofwhich only one gas-measuring device 8 is shown in FIG. 1 forsimplicity's sake. The concentration of carbon monoxide, hydrogensulfide and oxygen as gaseous substances is detected in the ppm range inthis exemplary embodiment. Further, the gas-measuring device 8 is of aportable design in this exemplary embodiment and can be carried along bya user. In this exemplary embodiment, the gas concentration monitoringsystem 2 has a main central unit 200 and two further auxiliary centralunits 201, 202, as a memory and analysis means and central units, whichhave a device each for checking the gas-measuring device for operabilityand will hereinafter be called docking stations 301, 302 forsimplicity's sake. The central unit 200 and the auxiliary central unit201, 202 are connected with one another in this exemplary embodiment viaa computer network for data exchange.

A data bank 40 is assigned to the main central unit 200 and a data bank41, 42 each is assigned to the auxiliary central units 201, 202. Acomputer each is assigned to each of the data banks 40, 41, 42, but onlythe computer 34 assigned to the main central unit 200 is shown inFIG. 1. However, it is obvious that a corresponding computer may be oris likewise assigned to each of the auxiliary central units 201, 202.

The computer 34 of the main central unit 200 has access to the data bank40, 41, 42 in this exemplary embodiment and can write data in the formof data sets 6 into the respective data bank 40, 41, 42 and read outsaid data.

To analyze the data sets 6, the computer 34 has an input interface 22, adata bank module 24, an analysis module 26 and a filter function 28, butFIG. 1 shows only the components that are assigned to the central unit200. These components may be designed as pure hardware components, aspure software components, or as a combination thereof, and they may thusbe part of a computer program product.

A data set 6 is input with the input interface 22; this data set 6 wasread out from the gas-measuring device 8 and was then stored in the databanks 42 of the two data banks 41, 42 and then transmitted later, e.g.,upon a prompt by the main central unit 200, to the data bank 40 of themain central unit 200 and was archived there.

The data bank module 24 of the computer, with which the data set 6 canbe read out and stored, is provided for this.

Via the data bank module 24, the analysis module 26 of the computer 34has access to the data set 6 being stored by the data bank module 24.The analysis module 26 is designed to analyze the data set 8 beingstored or a plurality of data sets 8 in order to determine the safetycode SK for rating the safety situation in a predetermined operatingarea.

The data sets 6 can be filtered with the filter function 28 with respectto the model of the gas-measuring device 8 and/or to the field of use ofthe gas-measuring device 8 and/or to the users of the gas-measuringdevice 8 and/or to the user groups of the gas-measuring device 8 and/orto the use time of the gas-measuring device 8. The result is a filtereddata set 36, which sends the filter function 28 back to the analysismodule 26, and which can then be analyzed by the analysis module 26 todetermine further, special safety codes SSK, as it will be explainedlater.

With additional reference to FIG. 2, the design of the auxiliary centralunits 201, 202 with their docking stations 301, 302 will be explainednow. As was mentioned already, the auxiliary central units 201, 202 havea data bank 41, 42 each, to which a computer each is likewise assigned,which has the same design as the computer 34 of the main central unit34, so that a detailed description of these components can be omittedhere, because they are identical.

Contrary to the central unit 200, the auxiliary central units 201, 202have a docking station 201, 202 each. Each of the docking stations 201,202 has a plurality of mounting sites 501, 502, 503, 504, 505 for agas-measuring device 8 each. Inserted into one of the mounting sites501, 502, 503, 504, 505, a bump test or a calibration can be performedwith the docking station 201, 202.

A mounting site interface 601, 602, 603, 604, 605, which is designed toestablish an electric contact between the docking station 301, 302 andthe gas-measuring device 8, is assigned to each of the mounting sites501, 502, 503, 504, 505. This makes it possible to transmit a data set 6from the gas-measuring device 8 to the auxiliary central units 201, 202to archive the data set 6 in the data bank 41, 42 (see FIG. 1).

Further, one docking station 201, 202 or each of the docking stations201, 202 may have an output means 38, e.g., in the form of a display,with which it can be displayed whether a bump test or a calibration wassuccessfully concluded, or is just being carried out. In addition, itcan be displayed with the display means 38 that a data set 6 wastransmitted or is just being transmitted. Finally, the content of thedata set 6 can be visualized with the display means 38, and the displaymeans 38 can be used to display the safety code SK. For example,different colors can be assigned to different value ranges of the safetycode SK, e.g., green to a quite safe safety situation, yellow to aprecarious safety situation, which requires increased attention, and redto a safety situation that requires immediate action.

Finally, the docking stations 301, 302 are designed to generate a resetsignal (see FIG. 1), with which—as will be described later—a deletionoperation is triggered after conclusion of a reading-out operation of adata set 6 and a new data set 6 is thus generated.

Reference will now be additionally made to FIG. 3.

The gas-measuring device 8 has, besides the gas sensor 10 for detectingat least one gaseous substance, an acceleration sensor 12, a comparisonmeans 14, a monitoring means 16, a data set generation module 18, and agas-measuring device interface 30 in this exemplary embodiment. Thecomparison means 14, the monitoring means 16, the data set generationmodule 18, and the gas-measuring device interface 30 may be designed aspure hardware components, as pure software components, or as acombination thereof.

Accelerations acting on the gas-measuring device 8 can be detected withthe acceleration sensor 12. These are in the form of acceleration dataBD and are transmitted to the data set generation module 18.

The comparison means 14 is designed to compare a measured value detectedwith the gas sensor 10 of the gas-measuring device 8 in the form of gasconcentration measured data GM with a gas concentration limit value,e.g., a workplace limit value (WLV) or with a lower explosion limit(LEL). The gas-measuring device 8 has two limit values for each gaseoussubstance in this exemplary embodiment, and an alarm is triggered whenthese limit values are exceeded. These are a low limit value, whoseexceeding triggers a pre-alarm (also called A1), and a high limit value,whose exceeding triggers a master alarm (also called A2).

The current measured value of the gas sensor 10 is read out during theoperation continuously or at fixed intervals and compared with the gasconcentration limit value. When the gas concentration limit value isexceeded, the comparison means 14 generates comparison data VD, whichare likewise transmitted to the data set generation module 18.

By contrast, the monitoring means 16 is designed to check whether aprescribed checking of the operability was performed, e.g., byperforming a calibration and/or a bump test of the gas-measuring device8, within a checking interval. The monitoring means 16 cooperates withone of the docking stations 201, 202, which generate a checkingconfirmation signal ÜS after a bump test or a calibration has beenperformed and transmit it to the monitoring means 16 of thegas-measuring device 8 after a bump test or a calibration has beenperformed. The monitoring means 16 will then monitor whether one of thecalibrations or bump tests was performed within the checking intervalintended herefor. If the monitoring means 16 detects a skipped checking,i.e., a bump test or calibration not performed within the prescribedinterval, this is available in the form of monitoring data ÜD, which aretransmitted to the data set generation module 18.

The data set generation module 18 generates a data set 8, which iswritten from the data set generation module 18 into the memory 32 of thegas-measuring device 8, from the acceleration data BD, the monitoringdata ÜD and the comparison data VD. The data set 8 being archived in thememory 32 can be read out, as was already described, via the interface30 directly from a docking station 201, 202 and indirectly, i.e., withintermediate storage in one of the data banks 41, 42 of the dockingstations 201, 202, from the central unit 200.

The mode of operation of the gas concentration monitoring system 2 willnow be explained on the basis of FIGS. 1 through 3.

Before it is put into operation, a gas-measuring device 8 is usually inone of the mounting sites 501, 502, 503, 504, 505 of one of the dockingstations 201, 202. The docking station 201, 202 has performed thenecessary bump test or the necessary calibration of the gas-measuringdevice 8 and then generated a reset signal RS and transmitted same viathe interface 30 of the gas-measuring device 8 to said gas-measuringdevice 8, which will then trigger a deletion operation of the memory 32of the gas-measuring device 8, so that a new data set 8 is generatedafter the gas-measuring device 8 is put into operation.

The gas-measuring device 8 is put into operation with the removal of thegas-measuring device 8 from the mounting site 501, 502, 503, 504, 505.The monitoring means 16 is now activated and it checks whether aprescribed checking for operability was performed within the checkinginterval by the performance of a calibration or of a bump test.

If, furthermore, the gas-measuring device 8 was activated such that itdetects gas concentrations with the gas sensor 10, the comparison means14 is also activated at the same time and it compares the defectedmeasured value in the form of gas concentration measured data GM withthe preset gas concentration limit value.

If the monitoring means 16 now determines that a prescribed check ofoperability by performing a bump test or a calibration was notperformed, or if the comparison means 14 determines that the preset gasconcentration limit value was exceeded, the data set generation module18 generates a data set 8 by analyzing the acceleration data BD, themonitoring data ÜD and/or the comparison data VD and stores this in thememory 32. Besides the information that a prescribed checking of thegas-measuring device 8 for operability was not performed, or that a gasconcentration limit value was exceeded, the data set 6 may contain agas-measuring device identification number of the gas-measuring device8, a model number of the gas-measuring device 8, gas concentrationmeasured data detected with the gas sensor 10 within a use interval ofthe gas-measuring device 8, the operating time or use interval durationof the gas-measuring device 8, acceleration values detected with anacceleration sensor 12 within a use interval of the gas-measuring device8, or a user identification number for identifying a user.

The gas-measuring device 8 is then again placed into one of the mountingsites of the docking stations 201, 202 and the use interval is thusended.

The data set 6 is now read out via the gas-measuring device interface 30of the gas-measuring device 8 and stored by the data bank module of thedocking station 302 in the assigned data bank 42. The data set 6 may beanalyzed, e.g., directly at the docking station 202 to determine thesafety code SK. However, provisions are made in this exemplaryembodiment for the data set 6 to be read out by the computer 34 of thecentral unit 200 via a computer network, and to be archived in the databank 40 of the central unit 200 via the input interface 22 and the databank module 24.

It is apparent that a plurality of data sets 6, which were obtained witha plurality of gas-measuring devices 8 during a plurality of useintervals, are archived in the data bank 40.

The majority of the data sets 6 being stored in the data bank 40 of thecentral unit 200 can be analyzed in a further step to determine thesafety code SK.

The determination of the safety code SK is carried out by the analysismodule 26 of the central unit 200. The analysis module 26 performs forthis a weighted addition:

-   -   of the number of skipped calibrations;    -   of the number of skipped bump tests; and    -   of the duration of the detected exceeding of the gas        concentration limit value within the use interval.

The duration of the detected exceeding of the gas concentration limitvalue within the use interval of the gas-measuring device is the averageduration of the alarm in this exemplary embodiment, i.e., the durationof a pre-alarm (A1) or of a master alarm (A2) of a plurality ofgas-measuring devices 8 of a fleet of gas-measuring devices pergas-measuring device in minutes, i.e., the total duration of the alarmof all gas-measuring devices of a fleet of gas-measuring devices,divided by the number of gas-measuring devices and standardized for thenumber of minutes of alarm per day.

The analysis module 26 uses three different weighting factors for theweighted addition. A first weighting factor is assigned to the number ofskipped calibrations, a second weighting factor is assigned to thenumber of skipped bump tests, and a third weighting factor is assignedto the duration of the detected exceeding of the gas concentration limitvalue.

The second weighting factor may be 1.5 to 3 times greater than the firstweighting factor. The second weighting factor is twice the firstweighting factor in this exemplary embodiment to have skipped bump testsbe reflected especially heavily in the safety code.

The third weighting factor may be, by contrast, 2 to 5 times the firstweighting factor. The third weighting factor is 3 times the firstweighting factor and 1.5 times the second weighting factor in thisexemplary embodiment, so that especially critical limit value exceedingsaffect the safety code especially strongly.

The analysis module 26 generates as a result a safety code SK, whichcontains information on how often limit values are exceeded and/or howconscientiously the gas-measuring devices 8 were checked on the basis ofthe information contained in the data set 8 on the limit value exceedingand/or the skipped checks of the gas-measuring devices. An intuitivelyeasy-to-understand safety code, in which the number zero is a very goodvalue and the scale of the safety code is open upwardly, i.e., it canassume any desired high value, is obtained by the weighted addition. Itis thus not suggested, unlike in the case of data expressed inpercentage, which may have a value ranging from zero to 100%, that thereis a 100% risk. The safety code SK determined can in turn be archived inthe data bank 40 of the central unit 200 and later compared with furthersafety codes SK determined later. Changes in the safety situation canthus be recognized in a simple manner.

Special safety codes SSK, which yield further, informative informationconcerning the model of the gas-measuring devices 8 used, the field ofuse of the gas-measuring devices 8, the users of the gas-measuringdevices 8, the user groups of the gas-measuring devices 8 and the usetime of the gas-measuring device 8, can be generated by means of thefilter function 28.

The data sets 6 archived in the data bank 40 are filtered for this bymeans of the filter function 28 in a first analysis step beforedetermining the respective special safety code SSK. The filter function28 is freely programmable, so that filtering of the data sets 6 withrespect to the model of the device, the field of use of thegas-measuring devices 8, the users of the gas-measuring devices 8, usergroups of the gas-measuring devices 8 or the use time of thegas-measuring devices 8 is possible.

A special safety code SSK, which contains information on the reliabilityof individual models of the fleet of devices, on the effect of the fieldof use of the gas-measuring devices 8 on reliability, on problems withhandling the gas-measuring devices by individual users or user groups orthe effect of the use time on the reliability of the gas-measuringdevices 8, is subsequently determined from the filtered data sets 6 in asecond analysis step. These special safety codes SSK can also bearchived in the data bank 40 of the central means 200 and compared overa longer time period with further special safety codes SSK determinedlater in order to make it possible to recognize changes in the safetysituation in a simple manner.

Further, the safety code SK and also the special safety codes SSK can betransmitted via the computer network to the docking stations 301, 302and displayed there with the display means 38 to inform users on thesafety situation when a gas-measuring device 8 is put into operation.

While specific embodiments of the invention have been shown anddescribed in detail to illustrate the application of the principles ofthe invention, it will be understood that the invention may be embodiedotherwise without departing from such principles.

We claim:
 1. A gas measuring arrangement comprising: a plurality ofmounting sites configured to perform one of a calibration test and abump test with a test gas, the calibration test with the test gasdetermining calibration parameters, the bump test being more rapid thanthe calibration test, said mounting sites being spaced from each other;a plurality of portable gas measuring devices, each of said plurality ofportable gas measuring device being portable relative to each other andsaid plurality of mounting sites, said plurality of gas measuringdevices being selectively movable into different parts of an operatingarea, said each gas measuring device including a gas sensor measuring agas concentration in the respective parts of the operating areasurrounding a respective said gas measuring device, said each gasmeasuring device storing measured values of the gas concentration, saideach gas measuring device being configured to be selectively docked inone of said plurality of mounting sites and configured to be selectivelyremovable from a respective said mounting site, said each gas measuringdevice being configured to be movable around a predetermined part of theoperating area relative to said central unit and other said gasmeasuring devices; said each gas measuring device being configured tocooperate with the test gas of a respective one of said mounting sitesto perform the one test, said each gas measuring device having a desiredinterval between the one test, said each gas measuring device recordingtest data indicating performance or nonperformance of the one test atone of the desired intervals; a central unit connected to said mountingsites, and receiving the stored measured values and the test results foreach of said gas measuring devices when the gas measuring devices arearranged in said mounting sites, said central unit generating a safetycode based on the stored measured values, and performance ornonperformance of the one test, from all of the plurality of gasmeasuring devices, said safety code identifying a safety situation ofthe different parts of the operating area; an output device connected tosaid central unit, said output device receiving and displaying thesafety code and informing an operator of the safety situation in thepredetermined operating area.
 2. An arrangement in accordance with claim1, wherein: said mounting sites perform both the calibration test andthe bump test; said each gas measuring device cooperating with saidrespective mounting site to perform both tests, said each gas measuringdevice having a separate desired interval between the both tests, saideach gas measuring device recording test data indicating performance ornonperformance of the both tests at the desired intervals; said centralunit determines the safety code from a weighted addition of the measuredvalues of the gas concentration and a number of non-performed bump testsand calibration tests of all said gas measuring devices.
 3. Anarrangement in accordance with claim 2, wherein: said central unitdetermines the safety code as a numerical value with a range from zeroat one end of the range with the other end being upwardly opened, thenumerical value of zero for the safety code indicating a safe value andhigher numbers being less safe.
 4. An arrangement in accordance withclaim 1, wherein: the stored measured values include informationregarding a duration of gas concentrations exceeding a gas concentrationlimit value, said central unit also determines the safety code from theduration of gas concentrations exceeding a gas concentration limitvalue.
 5. A method for determining a safety situation of an operatingarea with respect to gas, the method comprising the steps of: providinga plurality of gas measuring devices, each of said gas measuring devicescomprising at least one gas sensor measuring at least one gasconcentration; selectively moving the plurality of gas measuring devicesthrough different parts of an operating area; operating the plurality ofgas measuring devices in the different parts of the operating area tomeasure gas concentrations in the respective different parts of theoperating area; providing a plurality of mounting sites configured toperform one of a calibration test and a bump test with a test gas, thecalibration test with the test gas determining calibration parameters,the bump test being more rapid than the calibration test, the mountingsites being spaced from each other; performing the one of thecalibration test and bump test with the test gas of a respective one ofthe plurality of mounting sites, the each gas measuring device having adesired interval between the one test, the each gas measuring devicegenerating test data indicating performance or nonperformance of the onetest at one of the desired intervals; transmitting the test data and thestored measured values to a central unit; generating a safety code basedon the stored measured values, and performance or nonperformance of theone test, from all of the plurality of gas measuring devices, saidsafety code identifying a safety situation of the different parts of theoperating area; displaying the safety code; operating the operating areaas a function of the safety code.
 6. A method in accordance with claim5, further comprising an acceleration sensor in said plurality of gasmeasuring devices for detecting accelerations acting on thegas-measuring device.
 7. A method in accordance with claim 5, whereinthe gas-measuring device is designed to generate new data upon receivinga reset signal.
 8. A method in accordance with claim 5, wherein saidplurality of gas measuring devices are designed to generate data thatcontains at least one of: an identification number of the gas-measuringdevice; and model number of the gas-measuring device; and gasconcentration measured data detected with the gas sensor within a useinterval of the gas-measuring device; and an operating time, especiallyuse interval duration, of the gas-measuring device; and accelerationvalues detected with an acceleration sensor within a use interval of thegas-measuring device; and a user identification number for identifying auser of the gas-measuring device.